Fan negative wind direction independent variable pitch load reduction control method, system and equipment and medium

Abstract

The embodiment of the invention provides a fan negative wind direction independent variable pitch load reduction control method, system and equipment and a medium. The method comprises the steps that the negative wind direction deviation angle, the blade pitch angle and the blade azimuth angle of the wind turbine generator are obtained; whether the negative wind direction deviation angle exceeds a first deviation threshold value or not is judged, if yes, negative wind direction independent variable pitch control is conducted according to the blade azimuth angle, and meanwhile yaw wind facing is started; whether the negative wind direction deviation angle exceeds a second deviation threshold value or not is judged, if yes, negative wind direction independent variable pitch control is carried out according to the blade azimuth angle, meanwhile, yaw wind facing is forbidden, and shutdown protection is started; and whether the blade pitch angle is larger than the pitch angle threshold value or not is judged, if yes, negative wind direction independent variable pitch control is quitted, meanwhile, centralized feathering is started, yaw wind facing is released, and shutdown protection is started. According to the embodiment of the invention, multiple mechanisms of the fan are coordinated and matched to act through negative wind direction independent variable pitch control, so that the problem of overlarge load under the working condition of extreme wind direction change of the fan is solved, and the design cost of the fan is greatly reduced.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure belong to the technical field of wind turbine variable pitch control, and particularly relate to a wind turbine negative wind direction independent variable pitch load reduction control method, system, device and medium. BACKGROUND

[0002] Wind power has become the third largest power source in China. By 2025, non-fossil energy consumption will account for 20% of China's total energy consumption. In order to achieve the goal of "reaching carbon emission peak by 2030 and achieving carbon neutrality by 2060", China's wind power has developed rapidly. However, the profit of wind power equipment has not increased significantly. With the advent of the era of parity, the cost reduction pressure is huge. In order to reduce costs and improve product competitiveness, long blades, high towers, and large-capacity units are the overall trend.

[0003] Wind turbines often operate in relatively harsh environments. The rapid change of wind direction in the wind field can cause serious aerodynamic imbalance. Extreme changes in wind direction can cause the load of the unit to become larger and larger, posing a greater safety hazard to the operation of the unit and negatively affecting the economic benefits of the owner.

[0004] After the parity of wind power, the design of the unit is mainly large-scale and cost reduction. The load of large wind direction deviation working condition exceeds the design limit load, which becomes a key problem that puzzles the design of the unit. At present, the limit load design of the hub tower and other structural parts of large megawatt wind turbines cannot meet the requirements of extreme working conditions, thereby failing to pass the standard certification. Or the material cost increases sharply, resulting in serious losses. The method of reducing load by reducing the variable pitch rate has also lost its effect on long blade units. Currently, wind turbines are usually shut down for protection. However, even during shutdown, the unit is prone to exceed the load design requirements. SUMMARY

[0005] Embodiments of the present disclosure aim to at least solve one of the technical problems existing in the prior art, and provide a wind turbine negative wind direction independent variable pitch load reduction control method, system, device and medium.

[0006] One aspect of the present disclosure provides a wind turbine negative wind direction independent variable pitch load reduction control method, the method comprising:

[0007] obtaining a negative wind direction deviation angle, a blade pitch angle and a blade azimuth angle of a wind turbine;

[0008] determining whether the negative wind direction deviation angle exceeds a first deviation threshold, and if so, performing negative wind direction independent variable pitch control according to the blade azimuth angle, while starting yawing wind alignment;

[0009] determining whether the negative wind direction deviation angle exceeds a second deviation threshold, and if so, performing negative wind direction independent variable pitch control according to the blade azimuth angle, while disabling yawing wind alignment and starting shutdown protection;

[0010] Determine whether the blade pitch angle is greater than the pitch angle threshold. If it is, exit the independent pitch control in the negative wind direction, and at the same time start centralized feathering, unlock yaw against the wind, and start shutdown protection.

[0011] Furthermore, after performing independent pitch control in the negative wind direction and simultaneously activating yaw counter-wind, the method further includes:

[0012] Determine whether the negative wind direction deviation angle is lower than the third deviation threshold. If it is lower, exit the independent pitch control for negative wind direction.

[0013] Furthermore, the blade azimuth angle has a phase difference of 0° and 180°;

[0014] When the blade azimuth angle is 0°, the negative wind direction independent pitch control reduces the pitch angle to increase the angle of attack.

[0015] When the blade azimuth angle is 180°, the pitch angle of the independent pitch control in the negative wind direction increases to reduce the angle of attack.

[0016] Furthermore, the negative wind direction independent pitch control is expressed by the following formula:

[0017]

[0018] In the formula, β i (k) represents the pitch angle of the i-th blade at the current moment, β i (k-1) represents the pitch angle of the i-th blade at the previous moment, v represents the concentrated feathering speed requirement, T represents the program cycle period, and L represents the independent pitch angle in the negative wind direction. I represents the azimuth angle of the first blade, and I is the azimuth angle acquisition lag compensation value.

[0019] Another aspect of this disclosure provides a wind turbine negative wind direction independent pitch control system for load reduction, the system comprising:

[0020] The acquisition module is used to acquire the negative wind direction deviation angle, blade pitch angle, and blade azimuth angle of the wind turbine.

[0021] The first deviation judgment module is used to determine whether the negative wind direction deviation angle exceeds the first deviation threshold. If it exceeds the threshold, the negative wind direction independent pitch control is performed according to the blade azimuth angle, and yaw is activated to counter the wind.

[0022] The second deviation judgment module is used to determine whether the negative wind direction deviation angle exceeds the second deviation threshold. If it exceeds the threshold, the negative wind direction independent pitch control is performed according to the blade azimuth angle, while yaw is prohibited and shutdown protection is activated.

[0023] The blade pitch angle determination module is used to determine whether the blade pitch angle is greater than the pitch angle threshold. If it is greater, the independent pitch control in the negative wind direction is exited, and centralized feathering is started, yaw is unlocked, and shutdown protection is started.

[0024] Furthermore, the system also includes a third deviation judgment module, used to determine whether the negative wind direction deviation angle is lower than the third deviation threshold. If it is lower, the system exits the independent pitch control of the negative wind direction.

[0025] Furthermore, the blade azimuth angle has a phase difference of 0° and 180°;

[0026] When the blade azimuth angle is 0°, the negative wind direction independent pitch control reduces the pitch angle to increase the angle of attack.

[0027] When the blade azimuth angle is 180°, the pitch angle of the independent pitch control in the negative wind direction increases to reduce the angle of attack.

[0028] Furthermore, the negative wind direction independent pitch control is expressed by the following formula:

[0029]

[0030] In the formula, β i (k) represents the pitch angle of the i-th blade at the current moment, β i (k-1) represents the pitch angle of the i-th blade at the previous moment, v represents the concentrated feathering speed requirement, T represents the program cycle period, and L represents the independent pitch angle in the negative wind direction. I represents the azimuth angle of the first blade, and I is the azimuth angle acquisition lag compensation value.

[0031] Another aspect of this disclosure provides an electronic device, characterized in that it comprises:

[0032] At least one processor; and,

[0033] A memory communicatively connected to the at least one processor is used to store one or more programs that, when executed by the at least one processor, enable the at least one processor to implement the wind turbine negative wind direction independent pitch control method described above.

[0034] Another aspect of this disclosure provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the wind turbine negative wind direction independent pitch control method described above.

[0035] This disclosure discloses a wind turbine negative wind direction independent pitch control method, system, equipment, and medium. By controlling the negative wind direction independent pitch, the multiple actuators of the wind turbine coordinate their actions, which significantly reduces the load on the unit under large negative wind direction conditions. This is beneficial to the safe and stable operation of large megawatt wind turbine units without increasing hardware costs. It solves the problem of excessive load on wind turbine units under extreme wind direction changes and significantly reduces the design cost of the wind turbine by directly reducing the ultimate load of the unit. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the velocity triangle relationship when the blade is at a 0° azimuth angle;

[0037] Figure 2 This is a schematic diagram of the velocity triangle relationship when the blade is at a 180° azimuth angle.

[0038] Figure 3 This is a flowchart illustrating an embodiment of a wind turbine negative wind direction independent pitch control method for load reduction.

[0039] Figure 4 This is a simulation comparison diagram of the Mxy bending moment of a wheel hub according to an embodiment of this disclosure;

[0040] Figure 5 This is a simulation comparison diagram of the bending moment of the yaw bearing Mxy according to an embodiment of this disclosure;

[0041] Figure 6 This is a schematic diagram of the structure of a wind turbine negative wind direction independent pitch load reduction control system according to another embodiment of the present disclosure;

[0042] Figure 7 This is a schematic diagram of the structure of an electronic device according to another embodiment of the present disclosure. Detailed Implementation

[0043] The dlc1.4 operating condition specified in the wind turbine design standard IEC 61400-3:2005 simulates and addresses the requirements of rapid changes in wind direction. It is the most challenging condition to pass in load calculations, as the maximum load occurs during shutdown. Simulations show that this condition causes severe aerodynamic imbalance, resulting in extremely high loads on the turbine at the hub and yaw bearing center. Due to this condition, the rigidity and strength of components must be increased during design, leading to a significant increase in material usage and high equipment costs.

[0044] Currently, the conventional approach to dealing with this wind condition is to trigger shutdown protection when the wind direction deviation is detected to be greater than a set threshold. The shutdown process involves analyzing the difference in pitch retraction speed to find a shutdown solution that reduces the load during yaw shutdown. This approach only controls the pitch retraction speed during shutdown, resulting in limited load reduction. Even during shutdown, the unit is prone to exceeding load design requirements, leading to most extreme operating conditions in current load calculations occurring during large wind direction deviation shutdowns in the DLC1.4 operating condition.

[0045] Some researchers have attempted to use methods for ultra-short-term wind direction prediction to reduce load by prematurely stopping the turbine. However, this method has proven ineffective because ultra-short-term wind direction changes are unpredictable, and any advance prediction of wind direction is prone to significant errors. This results in the turbine failing to initiate premature pitch control during most extreme wind direction changes, and instead, sometimes starting with feathering to stop the turbine before reaching the required shutdown angle for protection, thus causing a loss of power generation.

[0046] The embodiments disclosed herein are based on large-megawatt units equipped with independent pitch control systems. Based on the understanding of the blade stress characteristics under yaw conditions, and according to the yaw deviation angle and blade azimuth angle information, the adjustment speed of the blades under different azimuth angles is independently planned, thereby reducing the aerodynamic imbalance of the wind turbine, and ultimately reducing the unit load and the unit design cost.

[0047] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.

[0048] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0049] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0050] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another. Therefore, the first component discussed below may be referred to as the second component without departing from the teachings of this disclosure. As used in this disclosure, the term "and / or" includes all combinations of any and more of the associated listed items.

[0051] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of exemplary embodiments, and the modules or processes in the drawings are not necessarily necessary for implementing this disclosure, and therefore cannot be used to limit the scope of protection of this disclosure.

[0052] The azimuth angle is the angle between the blade and the vertically upward line; it is 0° when the blade is vertically upward and 180° when it is vertically downward. For example... Figure 1 The diagram shows the velocity triangle relationship of the blade at a 0° azimuth angle, with relative wind speed V. ref The inflow angle θ is the vector sum of the incoming wind speed and the rotor speed. The inflow angle θ is the angle between the blade element linear velocity and the relative wind speed. The angle of attack α is the angle between the airfoil chord and the relative wind speed. The pitch angle β is the angle adjusted by the pitch control system. Load analysis under wind direction deviation shows that when the wind speed is negative and the azimuth angle is 0°, the angle of attack changes significantly with no relative yaw error. Specifically, the relative wind speed Vref increases, and the greater the negative wind direction deviation, the greater the corresponding relative wind speed Vref. While the relative wind speed Vref increases, the angle of attack decreases. The lift is proportional to the square of the relative wind speed and also proportional to the lift coefficient (within the non-stall range, the lift coefficient is proportional to the angle of attack). Therefore, it can be seen that in the case of no relative wind direction deviation, the magnitude of lift is related to the relative wind speed and the relative magnitude of the angle of attack change. That is, when the negative wind direction deviation is small, the relative wind speed change has a greater impact on lift, and lift increases with the increase of relative wind speed. When the negative wind direction deviation is large, the angle of attack change has a greater impact on lift, and finally lift decreases with the decrease of angle of attack.

[0053] like Figure 2 The diagram shows the velocity triangle relationship of the blade at a 180° azimuth angle. The load law analysis results are exactly the opposite of those at a 0° azimuth angle. The presence of negative wind direction deviation increases the airflow angle of attack, while the relative wind speed decreases. Similar to the analysis at a 0° azimuth angle, it can be seen that when the negative wind direction deviation is small, the change in relative wind speed has a greater impact on lift, and lift decreases as the relative wind speed decreases. When the negative wind direction deviation is large, the change in angle of attack has a greater impact on lift, and ultimately lift increases as the angle of attack increases.

[0054] Therefore, compared to the case of no wind direction deviation, the existence of a large negative wind direction deviation causes the blades to experience completely different aerodynamic lift and out-of-plane aerodynamic thrust at 0° and 180° azimuth angles. The uneven force on the blades at different azimuth angles causes the wind turbine to experience aerodynamic imbalance and overturning bending moment, which is the root cause of the ultimate load at the hub center under negative wind direction deviation. In addition, the weight of the blades and hub itself will cause the unit to bear the ultimate load at the yaw bearing, affecting the safety performance of the unit.

[0055] Negative wind direction reduces the angle of attack of the airflow, and pitch control itself further reduces the angle of attack. At this point, the angle of attack changes from positive to negative, causing a sharp decrease in positive lift until reverse thrust occurs. The greater the negative wind direction deviation, the larger the blade angle, and the greater the probability of reverse thrust. Simultaneously, within a certain range, the larger the blade angle, the greater the reverse thrust. The presence of negative wind direction deviation increases the angle of attack, while the increase in pitch angle reduces the angle of attack, thereby reducing blade lift and out-of-plane thrust.

[0056] In summary, during the negative wind direction feathering process, when the blade is at 0° azimuth, the angle of attack decreases until it becomes negative, causing the aerodynamic thrust to change from positive to negative. When the blade is at 180° azimuth, pitch adjustment causes the angle of attack to decrease, but due to the existence of the yaw angle, the angle of attack at 0° azimuth is significantly higher than that at 180° azimuth. This results in the thrust reduction at 0° azimuth being much greater than that at 180° azimuth, which ultimately leads to the ultimate overturning moment in the hub stationary coordinate system.

[0057] The stress characteristics of the blade element under positive wind direction are similar to those under negative wind direction. Ultimately, it also leads to the generation of an ultimate overturning moment during feathering after the wind direction deviation exceeds the limit, but in the opposite direction. This overturning moment can offset part of the moment generated by the weight of the wind turbine. At this time, it is not a severe stress state. Therefore, the stress under positive wind direction deviation does not need to be handled by special control measures.

[0058] The above analysis shows that, in order to fundamentally reduce the load, it is necessary to reduce the aerodynamic imbalance of the blades at azimuth angles of 0° and 180°.

[0059] like Figure 3 As shown, embodiments of this disclosure provide a method for independent pitch control of a wind turbine in negative wind direction, the method comprising:

[0060] Step S1: Obtain the negative wind direction deviation angle, blade pitch angle, and blade azimuth angle of the wind turbine.

[0061] Specifically, the current negative wind direction deviation angle of the wind turbine and the current pitch angle and azimuth angle of each blade are measured in real time by sensors, and the data can be stored in the onboard PLC.

[0062] Step S2: Determine whether the negative wind direction deviation angle exceeds the first deviation threshold. If it does, perform independent pitch control in the negative wind direction according to the blade azimuth angle, and simultaneously start yaw to counter the wind.

[0063] Specifically, an independent pitch control (IPC) system for a three-bladed wind turbine can independently send different pitch angle commands to the three blades, reflecting blade deviation control under different rotor azimuth angles. The original independent pitch control strategy does not consider wind direction deviation and has a significant load reduction effect on large components such as the hub. However, numerous studies and experiments have shown that the original independent pitch control strategy actually increases the load on large components when the wind direction deviation is large. Therefore, this embodiment proposes an improved negative wind direction independent pitch control strategy, which achieves the basic load reduction target while precisely overcoming the shortcomings of the original strategy.

[0064] Because the independent pitch system can adjust each blade individually at different azimuth angles, when the unit exceeds the limit due to negative wind direction deviation, negative wind direction independent pitch control is adopted. The azimuth angles of the three blades at the current moment obtained in the previous step S1 are used as the input of the negative wind direction independent pitch controller, and the pitch control command output by the negative wind direction independent pitch control logic is used to perform unit blade pitch control.

[0065] When the detected negative wind direction deviation angle exceeds the set first deviation threshold (e.g., -15°), i.e., when the negative wind direction deviation angle is less than -15°, the original pitch control strategy is stopped, and the independent pitch system is used to increase or decrease the pitch angle according to different blade azimuth angles to reduce blade stress imbalance and thus reduce load. At this time, the yaw system should be activated simultaneously to counter the wind and reduce yaw.

[0066] Due to the presence of negative wind direction, the angle of attack of the blade element decreases at 0° azimuth and increases at 180° azimuth, causing aerodynamic imbalance between the upper and lower sections. Therefore, the negative wind direction independent pitch control in this embodiment needs to decrease the pitch angle and increase the angle of attack when the blade is at 0° azimuth, thereby increasing the forward thrust or decreasing the reverse thrust; while increasing the pitch angle and decreasing the angle of attack when the blade is at 180° azimuth, thereby decreasing the thrust. Since the azimuth angles of different blades are different at the same time, the pitch angles that need to be adjusted for different blades are also different. Using negative wind direction independent pitch control, the blade pitch angle command is finely adjusted according to the blade azimuth angle. That is, based on the centralized feathering command output by the conventional control strategy of the pitch controller, a corresponding negative wind direction independent pitch control command is superimposed on each blade, thereby obtaining the final pitch angle setpoint value for each blade, ultimately reducing the overturning moment introduced by the uneven force on the rotor. The negative wind direction independent pitch control in this embodiment is expressed as follows:

[0067]

[0068] In the formula, β i (k) represents the pitch angle of the i-th blade at the current moment, βi (k-1) represents the pitch angle of the i-th blade at the previous moment, v represents the concentrated feathering demand velocity, T represents the program cycle period, and L represents the independent pitch angle in the negative wind direction (which can be 2° in this embodiment). Let be the azimuth angle of the first blade, then the azimuth angles of the second and third blades are respectively... and I represents the azimuth angle acquisition lag compensation value (in this embodiment, the value can be 3°).

[0069] Then, it is determined whether the negative wind direction deviation angle is lower than the set third deviation threshold (e.g., -3°). If it is lower than the third deviation threshold, i.e., greater than -3°, then the negative wind direction independent pitch control in this embodiment is exited and the original pitch control strategy is restored.

[0070] Step S3: Determine whether the negative wind direction deviation angle exceeds the second deviation threshold. If it does, perform independent pitch control in the negative wind direction according to the blade azimuth angle, and simultaneously prohibit yaw against the wind and activate shutdown protection.

[0071] Specifically, when the wind direction change is too extreme and the negative wind direction deviation angle continues to increase beyond the set second deviation threshold (e.g., -25°), the unit activates shutdown protection. The shutdown process at this time is still the one most prone to extreme loads, so independent pitch control with negative wind direction, as described above, is performed simultaneously. Normally, the yaw system can operate normally during shutdown, the independent pitch strategy is disengaged, and centralized feathering is switched. However, when the negative wind direction deviation angle exceeds the set second deviation threshold (i.e., less than -25°), the yaw system's windward movement must be prohibited. This is because the yaw speed against the wind is too slow relative to the negative wind direction deviation; for example, the maximum yaw speed of some aircraft models is only 0.0056° / s, but the disturbance torque introduced by the yaw is enormous. If this torque combines with the ultimate overturning curve, it will generate an even greater ultimate load. Therefore, independent pitch control with negative wind direction, as described above, must also be performed at this time, increasing or decreasing the pitch angle according to different blade azimuth angles to reduce blade stress imbalance and thus reduce shutdown load. At this time, the shutdown protection is still effective. The concentrated feathering demand speed v in the negative wind direction independent pitch control formula above is the pitch demand speed for shutdown protection.

[0072] Step S4: Determine whether the blade pitch angle is greater than the pitch angle threshold. If it is, exit the independent pitch control in the negative wind direction, and at the same time start centralized feathering, unlock yaw against the wind, and start shutdown protection.

[0073] Specifically, the pitch angles of the three blades at the current moment obtained in step S1 are used as the input of the negative wind direction independent pitch controller. When the pitch angle of the negative wind direction independent pitch controller gradually increases, and the pitch angles of each blade increase to above the pitch angle threshold (e.g., 55°), the rotor speed has already dropped very low, and the load is also very small. At this time, there is no need to superimpose the negative wind direction independent pitch control for pitch control. Instead, centralized feathering control can be used, and the pitch control degenerates into:

[0074]

[0075] In the formula, β i (k) represents the pitch angle of the i-th blade at the current moment, β i (k-1) represents the pitch angle of the i-th blade at the previous moment, v represents the required speed for concentrated feathering, and T represents the program cycle period. Based on the above formula, concentrated feathering continues until the pitch angle of each blade reaches the maximum pitch angle (generally taken as 90°), at which point the feathering stop operation is completed.

[0076] like Figure 4 , Figure 5 The figures show a comparison of the simulated bending moments of the hub and the yaw bearing under extreme negative wind direction changes triggering a shutdown of a wind turbine unit at a wind speed of 10.5 m / s. As can be seen from the figures, by applying the wind turbine independent pitch control method for reducing load under negative wind direction according to an embodiment of this disclosure, the wind turbine unit achieves significant load reduction under extreme negative wind direction conditions.

[0077] This disclosure discloses a wind turbine independent pitch control method for reducing load in negative wind direction. By controlling the independent pitch in negative wind direction, the multiple actuators of the wind turbine coordinate their actions, which significantly reduces the load on the unit under large negative wind direction conditions. This is beneficial to the safe and stable operation of large-megawatt wind turbine units without increasing hardware costs. It solves the problem of excessive load on wind turbine units under extreme wind direction changes and significantly reduces the design cost of the wind turbine by directly reducing the ultimate load of the unit.

[0078] like Figure 6 As shown, another embodiment of this disclosure provides a wind turbine negative wind direction independent pitch control system for load reduction, the system comprising:

[0079] The acquisition module 610 is used to acquire the negative wind direction deviation angle, blade pitch angle and blade azimuth angle of the wind turbine.

[0080] The first deviation judgment module 620 is used to determine whether the negative wind direction deviation angle exceeds the first deviation threshold. If it exceeds the threshold, it performs independent pitch control in the negative wind direction according to the blade azimuth angle and simultaneously activates yaw wind response.

[0081] The second deviation judgment module 630 is used to determine whether the negative wind direction deviation angle exceeds the second deviation threshold. If it exceeds the threshold, it performs independent pitch control in the negative wind direction according to the blade azimuth angle, while prohibiting yaw against the wind and starting the shutdown protection.

[0082] The blade pitch angle determination module 640 is used to determine whether the blade pitch angle is greater than the pitch angle threshold. If it is greater, it exits the independent pitch control in the negative wind direction, and at the same time starts centralized feathering, unlocks yaw against the wind, and starts shutdown protection.

[0083] For example, such as Figure 6 As shown, the system also includes a third deviation judgment module 650, which is used to determine whether the negative wind direction deviation angle is lower than the third deviation threshold. If it is lower, the system exits the negative wind direction independent pitch control.

[0084] For example, the blade azimuth angle has a phase difference of 0° and 180°;

[0085] When the blade azimuth angle is 0°, the negative wind direction independent pitch control reduces the pitch angle to increase the angle of attack.

[0086] When the blade azimuth angle is 180°, the pitch angle of the independent pitch control in the negative wind direction increases to reduce the angle of attack.

[0087] For example, the negative wind direction independent pitch control is expressed as follows:

[0088]

[0089] In the formula, β i (k) represents the pitch angle of the i-th blade at the current moment, β i (k-1) represents the pitch angle of the i-th blade at the previous moment, v represents the concentrated feathering speed requirement, T represents the program cycle period, and L represents the independent pitch angle in the negative wind direction. I represents the azimuth angle of the first blade, and I is the azimuth angle acquisition lag compensation value.

[0090] Specifically, the wind turbine negative wind direction independent pitch control system of this disclosure is used to implement the wind turbine negative wind direction independent pitch control method described in the above embodiments. The specific implementation process has been described in detail in the above embodiments, and will not be repeated here.

[0091] This disclosure discloses a wind turbine independent pitch control system for negative wind direction. By controlling the independent pitch of the wind turbine for negative wind direction, the multiple actuators of the wind turbine coordinate their actions, which significantly reduces the load on the unit under large negative wind direction conditions. This is beneficial to the safe and stable operation of large megawatt wind turbine units without increasing hardware costs. It solves the problem of excessive load on wind turbine units under extreme wind direction changes and significantly reduces the design cost of the wind turbine by directly reducing the ultimate load of the unit.

[0092] like Figure 7 As shown, another embodiment of this disclosure provides an electronic device, including:

[0093] At least one processor 701; and a memory 702 communicatively connected to the at least one processor 701 for storing one or more programs that, when executed by the at least one processor 701, enable the at least one processor 701 to implement the wind turbine negative wind direction independent pitch load reduction control method described above.

[0094] The memory 702 and processor 701 are connected via a bus, which can include any number of interconnecting buses and bridges. The bus connects various circuits of one or more processors 701 and memory 702 together. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. A bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by processor 701 is transmitted over a wireless medium via an antenna, which further receives data and transmits it to processor 701.

[0095] Processor 701 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory 702 can be used to store data used by processor 701 during operation.

[0096] Another embodiment of this disclosure provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the wind turbine negative wind direction independent pitch control method described above.

[0097] The computer-readable storage medium may be included in the systems or electronic devices disclosed herein, or it may exist independently.

[0098] Computer-readable storage media can be any tangible medium that contains or stores a program, and can be an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. More specific examples include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, optical fibers, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0099] Computer-readable storage media may also include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code, specific examples of which include, but are not limited to, electromagnetic signals, optical signals, or any suitable combination thereof.

[0100] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A method for independent pitch control and load reduction in the negative wind direction of a wind turbine, characterized in that, The method includes: Obtain the negative wind direction deviation angle, blade pitch angle, and blade azimuth angle of the wind turbine. Determine whether the negative wind direction deviation angle exceeds the first deviation threshold. If it does, perform independent pitch control in the negative wind direction based on the blade azimuth angle, and simultaneously initiate yaw wind countermeasure. Determine whether the negative wind direction deviation angle exceeds the second deviation threshold. If it does, perform independent pitch control in the negative wind direction based on the blade azimuth angle, while prohibiting yaw against the wind and initiating shutdown protection. Determine whether the blade pitch angle is greater than the pitch angle threshold. If it is, exit the independent pitch control in the negative wind direction, and at the same time start centralized feathering, unlock yaw against the wind, and start shutdown protection.

2. The method according to claim 1, characterized in that, After performing independent pitch control in the negative wind direction and simultaneously activating yaw to engage the wind, the method further includes: Determine whether the negative wind direction deviation angle is lower than the third deviation threshold. If it is lower, exit the independent pitch control for negative wind direction.

3. The method according to claim 1, characterized in that, The blade azimuth angle has a phase difference of 0° and 180°; When the blade azimuth angle is 0°, the negative wind direction independent pitch control reduces the pitch angle to increase the angle of attack. When the blade azimuth angle is 180°, the pitch angle of the independent pitch control in the negative wind direction increases to reduce the angle of attack.

4. The method according to any one of claims 1 to 3, characterized in that, The independent pitch control for negative wind direction is expressed by the following formula: In the formula, β i (k) represents the pitch angle of the i-th blade at the current moment, β i (k-1) represents the pitch angle of the i-th blade at the previous moment, v represents the concentrated feathering speed requirement, T represents the program cycle period, and L represents the independent pitch angle in the negative wind direction. I represents the azimuth angle of the first blade, and I is the azimuth angle acquisition lag compensation value.

5. A wind turbine negative wind direction independent pitch control system, characterized in that, The system includes: The acquisition module is used to acquire the negative wind direction deviation angle, blade pitch angle, and blade azimuth angle of the wind turbine. The first deviation judgment module is used to determine whether the negative wind direction deviation angle exceeds the first deviation threshold. If it exceeds the threshold, the negative wind direction independent pitch control is performed according to the blade azimuth angle, and yaw is activated to counter the wind. The second deviation judgment module is used to determine whether the negative wind direction deviation angle exceeds the second deviation threshold. If it exceeds the threshold, the negative wind direction independent pitch control is performed according to the blade azimuth angle, while yaw is prohibited and shutdown protection is activated. The blade pitch angle determination module is used to determine whether the blade pitch angle is greater than the pitch angle threshold. If it is greater, the independent pitch control in the negative wind direction is exited, and centralized feathering is started, yaw is unlocked, and shutdown protection is started.

6. The system according to claim 5, characterized in that, The system also includes a third deviation judgment module, which is used to determine whether the negative wind direction deviation angle is lower than the third deviation threshold. If it is lower, the system exits the independent pitch control of the negative wind direction.

7. The system according to claim 5, characterized in that, The blade azimuth angle has a phase difference of 0° and 180°; When the blade azimuth angle is 0°, the negative wind direction independent pitch control reduces the pitch angle to increase the angle of attack. When the blade azimuth angle is 180°, the pitch angle of the independent pitch control in the negative wind direction increases to reduce the angle of attack.

8. The system according to any one of claims 5 to 7, characterized in that, The independent pitch control for negative wind direction is expressed by the following formula: In the formula, β i (k) represents the pitch angle of the i-th blade at the current moment, β i (k-1) represents the pitch angle of the i-th blade at the previous moment, v represents the concentrated feathering speed requirement, T represents the program cycle period, and L represents the independent pitch angle in the negative wind direction. I represents the azimuth angle of the first blade, and I is the azimuth angle acquisition lag compensation value.

9. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor is used to store one or more programs that, when executed by the at least one processor, enable the at least one processor to implement the wind turbine negative wind direction independent pitch load reduction control method as described in any one of claims 1 to 4.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the wind turbine negative wind direction independent pitch control method for load reduction as described in any one of claims 1 to 4.

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